1. Field of the Invention
The present invention relates to a video signal level detector and, more particularly, to a video signal level detector for detecting a signal level of an input composite video signal for the purpose of recognizing and storing a receivable television channel.
2. Description of the Related Art
A television (TV) or a video tape recorder (VTR) is a video instrument which may be capable of performing a function of automatically detecting a receivable TV channel or storing the detected channel. To perform the automatic channel detection or storage function, such an instrument is constructed such that if the input signal level is greater than a predetermined value, it is determined that an input signal is receivable, and the input signal is stored.
In a conventional TV having the received channel automatic detection function, during automatic channel detection, adjacent channels may be also recognized to be receivable together with normal channels in an area or geographic location where the reception state is particularly good. In such a case, a user may manually remove the adjacent channels other than the normal channel from the channel storage device. This problem is caused by improved functions of broadcasting wave reception apparatus, tuners, and video signal processing integrated circuit (IC) technology, and by a lowering of the standards for determining selectivity of an input signal in consideration of areas having difficulty in viewing. Another cause of the problem is the comparison of the received level of a composite video signal among the input signals with a reference voltage to detect receivable channels.